One hundred moles of hydrogen gas at 298 k are reversibly and isothermally compressed from 30 to 10 liters. the van der waals constants for hydrogen are a = 0.2461 liters2 · atm· mole– 2 and b = 0.02668 liters/mole, and in the range of pressure 0– 1500 atm, the virial equation for hydrogen is pv = rt (1 + 6.4 × 10– 4 p ). calculate the work that must be done on the system to effect the required change in volume and compare this with the values that would be calculated assuming that
(a) hydrogen behaves as a van der waals fluid and
(b) hydrogen behaves as an ideal gas.

so here we go

atomic mass

239 + 1 = y + 134 + 3 combine like terms

240 = y + 137             subtract 137 from both terms

240 - 137 = y

103 = y

atomic number

94 = z +54 + 0

94 = z + 54               subtract 54 from both sides.

40 = z

answer

a). in this case, dh> 0 and sd> 0. if t becomes larger, the term "-tds" will become more negative. at some point, it is possible that -dts will be more negative than the dh is positive, and the reaction will become spontaneous. this is probably the correct answer, but you should look at all of the other possibilities and make sure of that.